US3838728A

US3838728A - Method for molding finger rings

Info

Publication number: US3838728A
Application number: US00366025A
Authority: US
Inventors: L Voegele
Original assignee: Jostens Inc
Current assignee: Jostens Inc
Priority date: 1973-06-01
Filing date: 1973-06-01
Publication date: 1974-10-01
Anticipated expiration: 1991-10-01

Abstract

A method of molding a finger ring having a hollowed out interior portion which includes forming a ring pattern by forming a first structure of a first moldable material in the shape of the final ring, dissolving a layer of desired thickness from such first structure, to form a second structure, forming a third structure by introducing a second moldable material into a cavity between the second structure and a molding apparatus, forming a fourth structure by dissolving all of said first material from said third structure, forming a fifth structure by introducing a third moldable material into a cavity between the fourth structure and an arbor, and finally, introducing a fourth moldable material into a cavity between the fifth structure and a molding apparatus.

Description

United States Patent [191' Voegele [451 Oct. 1, 1974 METHOD FOR MOLDING FINGER RINGS [75] Inventor: Lawrence R. Voegele, Owatonna,

Minn.

[73] Assignee: Jostens, Inc., Owatonna,.Minn.

[22] Filed: June 1, 1973 [21] Appl. No.: 366,025

[52] US. Cl 164/45, 249/57, 264/221, 264/227 [51] Int. Cl. B22c 7/02 [58] Field of Search 164/45; 249/57; 264/221, 264/227 [56] References Cited UNITED STATES PATENTS 3,302,257 2/1967 Kaplan 249/57 X 3,511,466 5/1970 Kaplan 249/57 3,601,178 8/1971 Marticorena 164/45 3,678,987 7/1972 Kydd 164/45 3,720,397 3/1973 Voegele 249/57 Primary Examiner-Robert D. Baldwin Assistant Examiner-John E. Roethel Attorney, Agent, or Firm-Dorsey, Marguart, Windhorst, West & I-lalladay [5 7] ABSTRACT A method of molding a finger ring having a hollowed out interior portion which includes forming a ring pattern by forming a first structure of a first moldable material in the shape of the final ring, dissolving a layer of desired thickness from such first structure, to form a second structure, fonning a third structure by introducing a second moldable material into a cavity between the second structure and a molding apparatus, forming a fourth structure by dissolving all of said first material from said third structure, forming a fifth structure 'by introducing a third moldable material into a cavity between the fourth structure and an arbor, and finally, introducing a fourth moldable material into a cavity between the fifth structure and a molding apparatus.

10 Claims, 6 Drawing Figures METHOD FOR MOLDING FINGER RINGS BACKGROUND OF THE INVENTION The present invention relates generally toa method of molding finger rings, and more specifically, to a method of molding finger rings having a hollowed out or recessed interior portion and a method of making the ring pattern for use in molding such finger rings.

Normally, scholastic rings such as those purchased by students as graduation and class rings, are molded from a relatively precious metal such as gold or silver. Such rings are molded throughout from this precious metal including the entire interior protion of the ring between the exterior surface thereof and the cylindrical bore which contacts the fingerof the wearer. These rings are relatively expensive due, in part, to the great amount of precious metal which is used in molding the ring. Further, such rings are quite heavy and retard the ability of the wearers finger to breathe during use because of the presence of this metal in the interior portion of the ring. Consequently, it is desirable in terms of reducing the cost and weight of such rings and providing comfort to the wearer to eliminate a portion of the precious metal which is used in the formation of these rings. One portion which is desirable to eliminate is that portion which exists between the exterior: surface of the ring and the portion which contacts the finger of the wearer. This portion of the ring performs little, if any, function and does not contribute to the external appearance of the ring. By reducing or eliminating the material which is molded in this portion of the ring, the cost of such a ring can be reduced substantially. It is desirable, however, for the hollowed out portion or the portion which is eliminated to substantially conform in all details to the exterior surface of the ring to enable the final molded ring to have a relatively uniform thickness throughout and to maximize the amount of material which can be eliminated. Although efforts have been made to mold rings with such a hollowed out interior portion, such methods have been unsatisfactory both from a cost standpoint and in terms of the quality of the hollowed out portion. One such method involved forming a ring pattern in a conventional manner and then hollowing out the interior portion manually. This method, however, required substantial expense because of the labor required to perform such hollowing out, and resulted in a ring pattern which did have a uniform thickness. Consequently, there is a real need in the finger ring molding field for an improved method by which finger rings may be molded with a hollowed out interior portion.

SUMMARY OF THE INVENTION ln contrast to the prior art, the present invention relates to a method of molding a finger ring having a hollowed out interior portion wherein the accomplishment of such method is relatively inexpensive and wherein the hollowed out portion conforms substantially, ex-

cept in smaller dimensions, to the details of the exterior uble in a first solution. After the wax material has sufficiently hardened. the mold structure is separated and the cylindrical arbor with the ring shaped wax structure mounted thereon is exposed to the first solution for a specified period of time in order to dissolve a layer of wax of desired thickness from the surface of such structure. Then, this partially dissolved wax model which is still mounted on the arbor is placed back into the mold structure and a second wax material which is nonsoluble in said first solution is introduced into the cavity formed between the exterior surface of the first wax model and the interior molding surface of the molding structure. When this has hardened sufficiently, the mold structure is again separated, the arbor removed from the resulting wax structure and the wax structure exposed to the first solution until the first wax portion of this structure has completely dissolved. The resulting structure, which is then composed entirely of the second wax material, is placed back onto the arbor and between the molding structures. A plastic molding material is then introduced into the cavity formed between the cylindrical arbor and the interior surface of the second wax material model and allowed to harden. After sufficient hardening, the resulting structure is removed from the molding structure and the exterior second wax portion is removed from the molded plastic portion which is molded to the arbor. This arbor, with the plastic portion now securely molded thereto, constitutes the final molding arbor for use in the ring molding method of the present invention. Finally, this molding arbor is placed between the molding structure and the ring is molded with a conventional process such as the lost wax or investment method of casting.

Accordingly, it is an object of the present invention to provide a method of molding a finger ring of the type having a hollowed out portion between the exterior surface of the ring and the finger of the wearer.

Another object of the present invention is to provide a relatively inexpensive method for molding a finger ring having a hollowed out portion wherein the hollowed out portion of said finger ring conforms substantially, in all details, to the exterior surface of the ring.

Another object of the present invention is to provide a method for molding a finger ring with a hollowed out portion wherein such finger ring has a relatively uniform thickness throughout.

Another object of the present invention is to provide a method for molding a finger ring with a hollowed out portion which includes a method of making a finger ring mold for the molding of such finger ring.

These and other objects of the present invention will become apparent with reference to the drawings, the description of the preferred method and embodiment for performing such method and the appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 4 is a view, partially in section, of the third intermediate mold structure which is formed during the ring molding process of the present invention.

FIG. 5 is a perspective view of an intermediate mold structure which is formed during the molding process of the present invention.

FIG. 6 is a perspective view of the final finger ring which has been formed and molded via the method of the present invention.

- DESCRIPTION OF THE PREFERRED METHOD AND EMBODIMENT FOR PERFORMING SUCH METHOD Reference is first made to FIG. I which illustrates an expanded view of the molding apparatus which is intended to be used in the performance of the molding method of the present invention. The molding apparatus of FIG. 1 includes a pair of molding members 11 and 12, a pair of

backing members

16 and 18 associated with the molding members 1 l and 12 respectively, a mandrel or arbor 19, and a plug 20. When combined together in their normal operative relationship, the pair of molding members 11 and 12, the arbor 19,-and the plug 20 form a first molding cavity into which a moldable material may be introduced to produce a pattern for the molding of an article such as a finger ring.

More specifically, each of the molding members 11 and 12 includes a flat, smooth surface area comprised of the surfaces 14,.14a and 14b and surfaces 15, a and 1512 respectively, which are designed for cooperative engagement when the molding members 11 and 12 are placed together in an operative position. Each of the surfaces 14a and 14b includes an alignment tab 21 adapted for correspondence with an alignment recess 22 located on each of the

surfaces

15a and 15b. When the surfaces 14a and 14b are placed in contact with the

surface

15a and 15b, the tabs 21 engage the recesses 22 to properly align the molding members 1 1 and 12. Each of the molding members 11 and 12 further includes, respectively, a semi-annular

beveled surface

24 and 25 for cooperation with a beveled surface 26 of the plug and a semi-cylindrical

interior surface

28 and 29 for engagement with the relatively cylindrical arbor 19.

The portions of the members 11 and 12, the plug 20 and the arbor 19 which actually contact the moldable material and form the first molding cavity include the

surfaces

32 and 34 of the members 11 and 12 respectively, the surface 33 of the plug 20 and the exterior cylindrical surface of the arbor 19. A sprue hole 35 is in communication with this first molding cavity and serves as a means for introducing the moldable material into such molding cavity.

The mandrel or arbor 19 is a relatively cylindrical member which, in the preferred embodiment, is composed of a plastic material. The arbor 19 is intended to engage the

semi-cylindrical surfaces

28 and 29 of, and be disposed between, the molding members 11 and 12. It should be noted that although the arbor 19 is shown as a single cylindrical member, it is contemplated that a pair of half arbors could be used in its place. As illustrated, the arbor 19 includes a pair of holes 36 extending therethrough for cooperation with a pair of alignment pins 38 which are also intended to extend into the

holes

39 and 40 in the

backing members

16 and 18 respectively to properly align the molding members 11 and I2 and the arbor 19.

Having now described the molding structure intended to be used in performing the method of the present invention, such method will now be described as follows: First, with reference to FIG. 1, the molding members 11 and 12, the arbor l9 and the plug 20 are placed together in an operative relationship so that a first molding cavity'is formed between such members. Then, a first moldable material which is soluble in a first solution is injected through the sprue hole 35 into the first molding cavity. In the preferred method, the first solution is water and the first moldable material is a water soluble wax which may be identified as No. 700 Light Green Water Soluble Wax manufactured by Casting Supply Company of New York, NY. Although it is contemplated that a variety of different types of waxes and materials may be used as the first moldable material, such material must be capable of dissolving uniformly from its surface when exposed to the solvent in which it is soluble. Further, the wax must be such that it does not soften when exposed to such solution. In the preferred method, the above identified first material was selected because it dissolved uniformly from its surface and because it met the other characteristics referred to above. Following the introduction of the water soluble wax into the first molding cavity, the wax therein is allowed to harden. After sufficient hardening, the mold sections 11 and 12 are separated from each other and the arbor 19 with the water soluble wax molded thereto is removed. This resulting structure, which shall hereinafter be referred to as the first intermediate mold structure, is similar to that which is illustrated in FIG. 2. With reference to FIG. 2, it can be seen that the first intermediate mold structure includes the arbor l9 and a water soluble wax ring model 41 molded thereto. The ring model 41 has an exterior appearance similar to that of the final ring product which is illustrated in FIG. 6. Extending downwardly from the model 41 is a sprue 42 which is formed during the molding process as a result of the introduction of water soluble material into the sprue hole 35 (FIG. 1).

Following removal of the first intermediate mold structure from the mold sections 11 and 12, it is immersed in water of approximately Fahrenheit. As soon as this structure is immersed into the water, the ring portion 41 and the sprue 42 which are composed of a water soluble wax begin to dissolve. Such dissolving is allowed to continue until the ring 41 and sprue 42 (FIG. 2) has been reduced to the desired size. It should be noted that during the dissolving process referred to above, only the portion of the ring 41 and the sprue 42 which is not in contact with the arbor I9 is dissolved, thus, the interior portion of the ring 41 which is in engagement with the exterior cylindrical surface of the arbor 19 is not affected by the water. After the desired dissolving has taken place, the arbor 19 with the ring structure 41 and sprue 42 mounted thereon is removed from the water and dried. In the preferred method, the desired dissolving has occurred when the diameter of the sprue 42 has been reduced by 0.050 inches. This means that a layer 0.025 inches thick will have been dissolved from the entire surface of the ring model 41.After completion of the dissolving step, the resulting structure, which shall hereinafter be referred to as the second intermediate mold structure, is illustrated in FIG. 3. As shown, the ring which is now identified by reference numeral 44 is reduced in size by approximately 0.025 inches over its entire surface and the sprue, now identified by reference numeral 45, is reduced in diameter by 0.050 inches. If desired, the edges of the ring 44 contacting the arbor 19 may be further cut away or routed manually to provide sufficient surface contact between the final ring and the finger.

Next, the second intermediate mold structure illustrated in FIG. 3 is placed between the molding sections 11 and 12 (FIG. 1) and the sections 11 and 12 are clamped together in an operative position. When this is accomplished, a molding cavity, which will hereinafter be referred to as the second molding cavity, is formed between the

surfaces

32 and 34 of the sections 11 and 12, the exterior surface of the ring 44 and sprue 45 (FIG. 3), and a portion of the arbor 19. This second molding cavity will be approximately 0.025 inches in thickness corresponding to the thickness of the layer which was dissolved during the dissolving step described above. A second moldable material is then introduced into the second molding cavity through the sprue hole 35 (FIG. 1) and allowed to harden. This second moldable material is a material which is nonsoluble in the first solution referred to above. Because the first solution in the preferred method is water, the second moldable material is a material which is not water soluble. More specifically, the second material is a non-water soluble wax which may be identified as H.P. granulated wax manufactured by Denton Precision Casting Supply Company of Warwick, Rhode Island.

After the non-water soluble wax introduced into the second cavity has been allowed to harden sufficiently, the mold sections 11 and 12 are separated and the resulting structure and arbor 19 are removed. At this point, the resulting structure, which shall hereinafter be referred to as the third intermediate mold structure, is very similar in appearance to that which is illustrated in FIG. 2, except that the structure has a portion composed of the first material (water soluble wax) and a portion composed of the second material (non-water soluble wax). As more clearly illustrated in FIG. 4, which shows a cross sectional view of the third intermediate mold structure, the ring model, which is now identified generally by the reference numeral 46, includes an inner portion 48 which is composed of a water soluble wax and an outer layer 49, approximately 0.025 inches in thickness, composed of a non-water soluble wax material. Similarly, the sprue includes an inner portion 56 composed of the first material and an outer portion 55 composed of the second material. The ring model structure 46 is then removed from the arbor 19 by cutting a portion of the ring band and peeling it off. The ring 46 is then submerged in water of approximately 100 Fahrenheit until the water soluble wax portion 48 has completely dissolved. In the preferred method it has been determined that immersion of the ring 46 in 100 Fahrenheit water for approximately minutes will dissolve the entire water soluble wax portion 48. Following the dissolving of the portion 48, the remaining structure, which shall hereinafter be referred to as the fourth intermediate mold structure,'includes only the portion 49 composed of a non-water soluble wax.

Following the dissolving of the portion 48 from the ring structure 46 of FIG. 4, the portion 49 (fourth intermediate mold structure) and the arbor 19 are placed between the mold sections 11 and 12. The mold sections 11 and 12 are then placed together forming a mold cavity, which will hereinafter be referred to as the third molding cavity; between the arbor l9 and the inner surface of the ring portion 49 (FIG. 4). A third moldable material is then poured into the third molding cavity through a hole (not shown) in the signet portion of the ring until the cavity is filled. This material is then allowed to cure. The third material is such that it bonds securely to the arbor 19 and, in the preferred method, is a plastic material which is known as L-l Castolite manufactured by The Castolite Company of Woodstock, Ill. After the third moldable material has sufficiently cured, the molding sections] 1 and 12 are separated and the arbor l9 and resulting structure bonded thereto is removed. At this point, the structure which shall hereinafter be referred to as the fifth intermediate mold structure, is similar in appearance to that illustrated in FIG. 4, however, it is composed of an exterior layer of the non-water soluble wax and an interior portion shaped similar to the portion 48 of FIG. 4 but composed of the third moldable plastic material. The exterior layer of non-water soluble wax is then peeled from the interior plastic portion and the resulting structure is then similar to the structure illustrated in FIG. 3. The sprue and a portion of the ring band are then manually removed from the fifth mold structure so that the final structure is similar to that illustrated in FIG. 5. As shown, a part of the band portion 53 of this structure is cut away. This is done on the palm side area of the ring to allow for sufficient finger size adjustment.

With the use of the mold structure illustrated in FIG.

5, the ring pattern which is used in molding the final ring product may be formed. To accomplish this, the structure which is illustrated in FIG. 5 is placed between the mold halves 11 and 12 (FIG. 1) and a ring pattern wax or fourth moldable material is introduced into the molding cavity formed between the molding surfaces of the members 1 l and 12 and the exterior surface of the structure illustrated in FIG. 5 through the sprue hole 35 (FIG. 1). When this wax has suff ciently hardened, the molding members 11 and 12 are separated and the resulting ring pattern (not shown) which now conforms substantially to the final ring product is removed from the arbor 19. The ring pattern is then used to form the final ring by a method which is known as the lost wax or investment method of casting. To accomplish this, the ring pattern is encased in an investment plaster material until the plaster is hardened. Then, the wax model is vaporized by use of extreme heat in a burn out furnace thereby leaving a pattern chamber in the plaster mold. Molten metal of the type which is desired to be used in the final ring product is then introduced into the pattern chamber and allowed to solidify. When sufficient hardening has taken place, the plaster is broken away leaving the solidified ring. As illustrated in FIG. 6, a gem or stone 52 and bezel 57 are then mounted to the ring 54 in a known manner. The

final ring 54 of FIG. 6-also includes a hollowed out interior portion 51 which is formed in accordance with the method of the present invention. This hollowed out portion enables a ring such as that illustrated in FIG. 6 to be molded from substantially less material than the methods of the prior art. Further, the ring 54 is of relatively uniform thickness throughout as a result of for mation via the method of the present invention.

Although the description of the preferred method of the ring molding method of the present invention has been quite specific, it is contemplated that various changes and modifications could be made without deviating from the spirit of this invention. Thus, the scope of the present invention is intended to be measured by the appended claims rather than by the description of the preferred method.

I claim:

1. A method of making a finger ring comprising the following method steps:

introducing a first moldable material which is soluble in a first solution into a first molding cavity formed by at least two molding sections and an arbor to form a first structure;

exposing said first structure to said first solution to form a second structure;

introducing a second moldable material which is nonsoluble in said first solution into a second cavity formed between said molding sections and said second structure to form a third structure;

exposing said third structure to said first solution to form a fourth structure; introducing a third moldable material into a third cavity formed between said fourth structure and said arbor to form a fifth structure; and

introducing a fourth moldable material into a fourth cavity formed between said fifth structure and said molding sections.

2. The method of claim 1 including exposing said third structure to said first solution until all of said first moldable material has dissolved therefrom.

3. The method of claim 1 wherein saidfirst solution is water, said first moldable material is a water soluble wax and said second moldable material is a non-water soluble wax.

4. The method of claim 1 wherein the introduction of said fourth moldable material into said fourth cavity results in the formation of a finger ring pattern.

5. The method of claim 4 including encasing said finger ring pattern in an investment plaster material and molding a finger ring via the investment method of casting.

6. The method of claim 1 including exposing said first structure to said first solution until a layer of desired thickness has been dissolved from the surface of said first structure.

7. The method of claim 6 including exposing said first structure to said first solution until a layer approximately 0.025 inches thick has been dissolved from the surface of said first structure.

8. The method of claim 1 wherein the step of forming said fifth structure includes allowing said third moldable material to harden and removing said fourth structure from the hardened third moldable material.

9. The method of claim 8 wherein said fifth structure includes a portion of said third moldable material securely bonded to said arbor.

10. A method of molding a finger ring which comprises the following method steps:

forming a first structure by introducing a first moldable material which is water soluble into a first molding cavity formed by at least two molding sections and an arbor extending therebetween;

forming a second structure by removing the arbor with said first structure molded thereto and exposing said first structure to water for a preselected time to dissolve away a layer of desired thickness from the surface of said first structure;

forming a third structure by placing said second structure and said arbor between said molding sections and introducing a second moldable material which is non-soluble in water into a second molding cavity formed between the molding sections and the second structure;

forming a fourth structure by removing said third structure from said molding sections and said arbor and exposing said third intermediate mold structure to water until all of the first moldable material has dissolved from said third structure;

forming a fifth structure by placing said fourth structure and said arbor between said mold sections and introducing a third moldable material into a third molding cavity fonned between said fourth structure;

forming a finger ring pattern by removing said fifth structure with said arbor molded thereto from said molding sections and removing the second moldable niaterial therefrom and introducing a fourth moldable material into a fourth cavity formed between said fifth structure and the molding sections.

forming a finger ring from said finger ring pattern via the investment method of casting.

Claims

1. A method of making a finger ring comprising the following method steps: introducing a first moldable material which is soluble in a first solution into a first molding cavity formed by at least two molding sections and an arbor to form a first structure; exposing said first structure to said first solution to form a second structure; introducing a second moldable material which is non-soluble in said first solution into a second cavity formed between said molding sections and said second structure to form a third structure; exposing said third structure to said first solution to form a fourth structure; introducing a third moldable material into a third cavity formed between said fourth structure and said arbor to form a fifth structure; and introducing a fourth moldable material into a fourth cavity formed between said fifth structure and said molding sections.

3. The method of claim 1 wherein said first solution is water, said first moldable material is a water soluble wax and said second moldable material is a non-water soluble wax.

10. A method of molding a finger ring which comprises the following method steps: forming a first structure by introducing a first moldable material which is water soluble into a first molding cavity formed by at least two molding sections and an arbor extending therebetween; forming a second structure by removing the arbor with said first structure molded thereto and exposing said first structure to water for a preselected time to dissolve away a layer of desired thickness from the surface of said first structure; forming a third structure by placing said second structure and said arbor between said molding sections and introducing a second moldable material which is non-soluble in water into a second molding cavity formed between the molding sections and the second structure; forming a fourth structure by removing said third structure from said molding sections and said arbor and exposing said third intermediate mold structure to water until all of the first moldable material has dissolved from said third structure; forming a fifth structure by placing said fourth structure and said arbor between said mold sections and introducing a third moldable material into a third molding cavity formed between said fourth structure; forming a finger ring pattern by removing said fifth structure with said arbor molded thereto from said molding sections and removing the second moldable material therefrom and introducing a fourth moldable material into a fourth cavity formed between said fifth structure and the molding sections. forming a finger ring from said finger ring pattern via the investment method of casting.